1. Field of the Invention
This invention relates to a supporting structure for an AT plate oscillator, i.e. a thickness-shear type crystal oscillator for watches.
2. Description of the Prior Art
Heretofore it has been the common practice to use an annular thickness-shear type crystal oscillator as shown in FIG. 1. That is, provision is made of a supporting member composed of a pair of electrically conductive supporting wires 15, 15 connected at respective rear ends to stems 17, 17 extending through an insulating substrate 18 and provided at respective front ends with coil-shaped portions 15a, 15a, respectively. Between those coil-shaped portions 15a, 15a are sandwiched diametrically opposite ends of a crystal piece 16. These ends of the crystal piece 16 are then firmly secured to the coil-shaped portions 15a, 15a by means of an electrically conductive paint or the like. Such crystal oscillator used as a time reference of a portable timepiece could not resist against shocks and oscillations subjected thereto from the outside.
In addition, a capsule 19 for enclosing the crystal piece 16 and fitted to the insulating substrate 18 becomes large in volume if compared with a size of the crystal piece, so that such crystal oscillator is not suitable for portable timepieces which are requested to be small in size.